PC ports explained: Get to know the back of your computer

Almost any modern communication need can be handled with a wireless solution. File transfer, streaming video, peripheral connections – all of these can be accomplished without a physical connection. The future is now.

Yet the port persists. No, more than that: It’s alive and well. Take a gander at your home office and you’ll likely find wires of all sorts leading to various connections: USB, HDMI, DVI, Thunderbolt, the list goes on.

Physical connections are still the quickest, most reliable way to transfer data. Which means it’s still important to know what goes where, and why. Let’s clear the air and make room for some modern knowledge of old-fashioned connectivity.

USB

The Universal Serial Bus would make a good role model for super-villains everywhere. It pledged to take over the world. Then it did so. It took well over a decade, but it has happened. FireWire is basically obsolete. External SATA is nearly extinct. Only Thunderbolt may provide a serious challenge – but it’s years away from widespread adoption.

Modern USB essentially comes in two forms – USB 2.0 and USB 3.0. The ports look the same and are compatible with each other, which is great. Except it makes separating the two difficult. Manufacturers the world over have tried to resolve the standard says that USB 3.0 ports should be blue or should be identified by super-speed USB 3.0 logo (see below).

If it’s not blue or identified by this logo, it’s not USB 3.0. Or at least it shouldn’t be. We’ve yet to encounter a computer that failed to identify USB 3.0 ports by at least logo, but we have run into a couple (both laptops) that didn’t use blue.

The main difference between the standards is speed. The maximum bandwidth of 3.0 is over 10 times higher than 2.0. This doesn’t mean transfer speeds are ten times better in the real world, but there is a huge difference. You’ll see much quicker file transfers with a USB 3.0 drive plugged in to a 3.0 port. Transfer speeds are not better if you plug a 3.0 drive into a 2.0 port. Data can still be transferred, but only at 2.0 speeds.

FireWire

FireWire was developed by Apple to solve the lack of high-speed connections available to peripherals during the early 90s. Speed was given high priority, and it showed in the resulting standard. FireWire which went through several revisions, and each was consistently quicker than USB.

Until now. USB 3.0 has upped the ante, and instead of calling, FireWire’s supporters have chosen to fold. It was probably a wise move. FireWire never gained the widespread appeal of USB. Losing its performance advantage made it nearly obsolete.

Still, many people have an older camera or peripheral which must be connected via FireWire. If you’re among this crowd you will need to plan on using adapters in the future. FireWire support is near extinction in the laptop space and nearly dead among desktops as well.

eSATA

This standard related to the common SATA standard that’s used by nearly all modern hard drives, but designed for external peripherals. It takes advantage of SATA’s excellent bandwidth to provide fast transfer speeds.

Sounds great, right? But there are a couple problems. One is a lack of support for power in the standard. USB and FireWire are both capable of powering devices, which is why most USB peripherals and storage devices don’t need external power. There’s no support for that in eSATA. A work-around port called eSATAp fixes that, but this port is rare and not part of the official SATA standard.

Another issue is the standard’s maximum cable length. SATA was built for use in computers, so the cables only had to work short distances. This means the maximum length of cable is six feet, six inches. Larger cables can be made, of course — it wouldn’t cause the space-time continuum to collapse — but they also wouldn’t be guaranteed to work.

Thunderbolt

Thunderbolt is a new type of connection developed by Intel under the codename Light Peak. As that name suggests, Thunderbolt was initially intended to be a fiber-optic connection capable of 10 Gbit/s (nearly twice the bandwidth of USB 3.0) but Intel engineers figured out how to accomplish this goal using only copper wire. This made Thunderbolt less expensive and gave it the ability to deliver power, a critical trait for any connection that dreams of widespread adoption. In fact, Thunderbolt can deliver a whopping 10 watts, which is over twice as much as USB 3.0.

This connection also doubles as a DisplayPort 1.2-compatible A/V connection. It’s possible to daisy-chain up to seven different devices (both displays and peripherals) off one Thunderbolt port, though there are limitations based on the types of devices connected.

Thunderbolt seems set to one day replace USB 3.0, but for now it remains expensive and only a handful of companies have adopted it. Apple was first to include it on production PCs. Other manufacturers are beginning to follow this lead, but only on high-end products. Even if you do have the port, there’s not much to connect to it besides DisplayPort-compatible monitors and a small (but growing) selection of external hard drives.

If you plan to buy a computer in 2014, consider this a must-have. For now it’s a great technology that needs to gain market acceptance.

DVI

Now it’s time to jump away from the general-purpose connections and start talking about those dedicated only to audio and video. DVI seems like a good place to start.

DVI is the old man of modern video connections. Its bloodline dates all the way back to 1999 and it didn’t see widespread acceptance until 2002 and 2003. Since then, it has resisted several different attempts to completely replace it, though its strength does seem to be fading.

Because it was developed as a successor to VGA, this connection can handle analog signals. That’s not going to be a factor for most readers but it may be worth noting if you still have an old VGA monitor kicking around. DVI also can output audio when paired with an appropriate video card and a DVI-to-HDMI adapter.

DisplayPort

DisplayPort was one of two A/V connections (the other being HDMI) developed in the middle of last decade. This connection was developed specifically with computer monitors in mind and is meant to be the full-digital replacement for DVI.

On paper, DisplayPort is a technical masterpiece. It has a maximum data rate of up to 18 Gbp/s in best fighting form. Like its sibling, Thunderbolt, DisplayPort allows for daisy-chain configurations. It’s possible to run up to four 1080p displays with a single DisplayPort connection. Another nice advantage is cable length: The spec supports up to three meters in copper and fifteen with fiber-optic – but be warned, those cables are expensive.

This connection is very good, but only if you have a monitor that supports it. Many inexpensive monitors don’t. The consumer television market is the culprit. Consumers usually know of HDMI, but few know of DisplayPort, which makes it hard to sell. Even so, this connection’s compatibility with Thunderbolt may make it the video standard of the future.

HDMI

The High Definition Multimedia Interface began production in 2003 as a replacement to all earlier A/V connections. It was built to be a do-it-all cable combining uncompressed audio and video for maximum picture quality.

Computers were never the focus. HDMI was developed for the expected surge of high-definition televisions. But the traits that make HDMI good for televisions also make it good for computers. This connection can handle audio and video with one cable. Better still, the connector is thin and flat, making HDMI great for laptops and other small systems.

All of these advantages also apply to DisplayPort, a connection that has several additional traits that make it technically superior to HDMI. Despite this, HDMI is more common. It’s often standard on inexpensive monitors and on laptops.

Despite be technically inferior in some ways, HDMI is more than adequate for most users. It’s a simple, easy plug that can handle high display resolutions. Its downsides, such as the inability to daisy-chain and shorter cable lengths, usually aren’t a concern.

Ethernet

Most computers now have wireless Internet available, yet Ethernet persists and is used in millions of homes worldwide. This simple connector, which looks a bit like a phone jack, has served the needs of networks for three decades.

Ethernet is most often used to connect to the Internet. It usually doesn’t offer any effective bandwidth advantage because the bandwidth of a strong wireless connection will almost certainly exceed the bandwidth of your Internet connection. Ethernet is more reliable, however. There’s no need to worry about signal interference, concrete walls and other obstructions.

Ethernet’s speed can be used to its full potential on a home network if appropriate routers and cables are used. Two computers networked with Gigabit Ethernet can transfer data at high speeds over relatively long distances.

Copper still rules

Ports matter, and we’ll probably be dealing with them for some time. Wireless bandwidth is now technically capable of handling HD video and can provide excellent data transfer rates, but expensive adapters are still required and reliability isn’t perfect in all environments. Cables, and the ports they plug in to, remain a cheap, reliable, simple solution. Hopefully this guide has helped you understand the galaxy of ports that are commonly used.